Fuse-plug for grenades



F. 1. LEBLANC. FUSE I LUG FOB GRENADES. APPLICATION FILED. JULY 19.1918.

Patented Mar. 8,1921.

ATTOR/VEKS UNITED STATES raraur orries.

FUSE-PLUG FOR GRENAIDES.

Application filed July 19,

To all whom it may concern:

Be it known that I, FERDINAND LAMnnnr LEBLANO, a citizen of the FrenchRepublic, of 46 Rue Lamartine, Paris, France, engineer, have inventedImprovements in Fuse- Plugs for Grenades, of which the following is afull, clear, and exact description.

The subject of this invention is an 1mprovement in fuse plugs forgrenades.

In the grenades with fuses now known, the mounting of the detonator isgenerally effected by double pressing or bezeling operationszthedetonator is first pressed or set by bezeling on the fuse cord, then onto the detonator is pressed or bezeled the extremity of the fuse plugtube in which the whole of the detonator and fuse cord are packed.

This 'mounting by double pressing or bezeling operations has variousinconveniences:

1st. By reason of a difference between the exterior diameter of the cordand the interior diameter of the detonator, an eccentricity of the cordwith reference to the detonator is often produced by the operation ofpressing or bezeling the latter and from this it results that onignition of the cord, the flame instead of being roj ected through thecentral aperture in t e diaphragm of the detonator, strikes theunperforated part *of this diaphragm and does not act on the explosivematerial of the detonator.

2nd. This double pressing or bezeling requires special tooling and cangenerally be effected only behind the front, so that the fuse plugs haveto be sent out provided with detonators, the transport of these fuseplugs necessitating in consequence, special packing and careful handlingand in spite of all precautions taken to avoid exposing the detonatorsto any shocks, the transport and handling of these fuse plugs alwayspresent some danger.

Moreover, in the grenades now known, the explosive charge is oftenexposed to deterioration by exterior agents, especially humidity,grenades at times become useless after a certain period.

Lastly, the transport and handlmg of these loaded grenades are alwaysdangerous.

This invention relates to an improved arrangement remedying theinconveniences pointed out above.

This improvement is essentially characterized by the two featuresfollowing:

1st. A special arrangement of the mount- Specification of LettersPatent.

and it results therefrom that these 1918. Serial No. 245,761.

ing of the detonator which always'insures its perfect concentricity withreference to the fuse cord and which permits a simple, easy and rapidadaptation or fitting of this detonator to the fuse plug.

2nd. The provision of an insulating sleeve mounted in the interior ofthe body of the grenade, and in which the fuse plug is placed and fixed.1

The annexed drawing shows by way of example, this improved arrangement.Flgure 1 shows a grenade provided with its fuse plug, in verticalsection. Fig. 2 shows to a larger scale, the mountmg of the detonator onthe fuse plug tube.

F 1g. 3 shows the insulating sleeve in elevation.

Fig. 4: shows a grenade and insulating sleeve in section.

Fig. 5 is a view in elevation of a fuse plug without its detonator, and

Fig. 6 shows a detonator, partly in sectllon, intended to be mounted onthe said fuse p ug.

In this improved arrangement, the tube a of the fuse plug in which thefuse cord 7) is lodged, has an internal diameter so determined that thisfuse cord may be engaged therein with slight friction. In order torender impossible the passage of gas between the interior wall of thistube a and the fuse cord 6, the end of the tube a is subjected to adrawing operation after the cord is put in position, in such a mannerthat this tube a is firmly pressed against the cord.

Thetube a has formed at its lower end a central orifice 0 correspondingto the axis of the fuse cord and has moreover an exterior shoulder (Zand terminates in a slightly conical part c on which the detonator f ismounted as will be hereinafter stated. The mean diameter of this conicalpart is equal to the interior diameter of the detonator. The latter isengaged firmly by friction on the said conical part 6 and its positionis limited by the shoulder d (Fig. 2).

By this arrangement, the axis of the detonator f coincides exactly withthat of the fuse cord 1); consequently, when the latter is ignited, theflame produced flashes out exactly in the axis of the detonator andalways passes through the central aperture 9 in the diaphragm h of thispart, and under these conditions the operation of the detonator isalways assured.

Moreover, by this arrangement the mounting of the detonator on the fuseplug can be Patented Mar. *8, 19 21.

effected without tooling in a simple and when required for immediateuse;the fuse plugs and the detonators can therefore be sent out separately,the detonators packed by themselves by reason of their shape will occupya minimum space. It is'therefore possible to send a large number of themin a small space and in these conditions their carriage can be effectedvery easily with all desired security. The fuse plugs unprovided withdetonators can be packed with out any special precaution since they donot comprise any dangerous explosive material.

The fuse plug thus furnished with its detonator is introduced into aninsulating sleeve mounted in the interior of the body of the grenade.This sleeve which'is made so as to conform to the exterior profile ofthe ignition device, comprises a tubez' closed at itslower part and abush j fixed'to this tube; this bush j is screw-threaded exteriorly insuch a manner that it can be screwed into the body of the grenade and istapped interiorly in, order to permit the fuse plug to be mountedtherein by screwing.

It is to be understood that theinsulating sleeve can be fixed in thebody of the grenade and the fuse plug can be fixed in the insulatingsleeve in any other convenien manner.

The insulating sleeve when mounted in the body of the grenade 70 servesto close the latter completely and to protect the ex plosive chargewhich it contains from the action of exterior agents especially fromhumidity; the body of the grenade 70 thus 7 closed by the bush 7' of theinsulating sleeve (Fig. 4), can be charged and transported in thiscondition without being furnished with a fuse plug.

By this invention grenades can thus be sent out in three parts:

1. The body of the grenade provided with its insulating sleeve andfilled of explosive (Fig. 4:)-

with a charge 7 (Fig. 5) and 3. The detonator 7 (Fig.6). The improvementwhich is the subject of this invention therefore offers a maximumsecurity 'of manipulation, transport and mounting of its parts.

' The form, dimensions and details of construction of this improvedarrangement can be varied according to its different applications.

Claims:

1. In a grenade, a fuse plug, atube extending therefrom, a fuse cordfrictionally held in said tube, a conical extension at the 2. The fuseplug without its detonator closed at its lower end and provided at itsopposite end 7 with a threaded bushing, whereby the fuse plug may bescrewed into said bushing and the tube of the fuse plug and thedetonator contained in the insulating sleeve, said bushing exteriorlyscrew threaded, whereby it may be screwed into the body ofthe grenade.-

2. In a grenade, a fuse plug, a tubular extension at one end thereof, afuse cord frictionally held therein, the free end of said tube beingconical, a central orifice formed at thelower end of the tube so thatthe flame produced when the fuse cord is ignited flashes axially out ofsaid tube, a detonator carried on the conical portion of said tube, anda transverse diaphragm within the detonator having a central openingtherethrough in axial alinement with the orifice of the conical end ofthe aforesaid extension.

' FERDINAND LAMBERT LEBLANC.

Witnesses: V

JOHN F. SIMoNs, 'FRANQOIS WEBER.

free end of the said tube, a central orifice V

